Signaling apparatus for grade crossings



June 1941' E. WILCKENS SIGNALING APPARATUS FOR GRADE CROSSINGS Filed Aug. 26, 1937 5 Sheets-Sheet 1 HEM INVENTOR ERNST W! LC KENS ATTORNEYS June 17, 1941. E. WILCKENS 2,246,025

smmune APPARATUS FOR GRADE cRossmcTs Filed Aug. 26, 1937 a Sheets-Sheet? INVENTOR' J ERNST WlLC KENS- 7mm my A T RNEYs June 17, 1941. wlLCKENS 2,246,025

SIGNALING APPARATUS FOR GRADE cnossmes Filed Aug. 26, 1937 3 Sheets-Sheet 3 INVENTOR ERNST W/LCKENS A TTOR IVEVS Patented June 17, 1941 r I oFFI-C E if? SIGNALING APPARATUS FOR GRAD E- CROSSINGS Ernst Wilckens, Berlin-Sudende, Germany, as

signer to Julius Pintsch Kommanditgesellschaft,

Berlin, Germany Application August 26, 1937, Serial No. 160,972 In Germany April 2, 1937 Claims. (Cl. 246-125) Signaling apparatus, intended for ensuring the safety of trafiic, are working in many cases with two different signals. Thus, for instance, the administration of railway trafiic works with green light as safe light and red light as block light. In signaling installations serving for regulating the traffic at crossingand railway tracks, a white flash li ht is provided for indicating clear way, as well as for showing that a signaling device has been provided atthis point for the purpose of safeguarding the crossing. Red flash light is to stop the road trafilc, because the approach of a railway train is indicated thereby.

Signaling installations of this nature, are fed 2 either by mean of storage batteries or primary batteries. They are also connected immediately to D. C. and A. C. supplies, in many cases in conjunction with the interpolation of buffer batteries.

In installations, which are connected immedi. atelyto a long distance-, municipalorstationcircuit and which have no current reserve to provide for breakdown or failure of this circuit, the two signals will not work so that no signaling can take place. This indicates to the road user that the installation has broken down and that he must not continue his wayiuntil hehas satisfiedvhimself that the Way is clearfor traffic.

So far two arrangements have been provided I in connection with the re-appearance of the cire cuit voltage. The first arrangement switches in the ordinary Operating or safe? light signal. The second arrangement provides the switching in of the warning or bloclnng signal. In installations, in which the interruption of the circuit may possibly cause a wrong signal being shown after return of the operating voltage, it has so far been decided, for reasons of safety, to cause the warning or blocking signal to light; up again 'block section again before the ately energized if there isa train on that-section of the track controlling the signals but. whenthe track becomes clear of trains the signal circuit will be restored to normal condition. The special switching device thus has, in some sort, the efiect that the blocking section or warning track will be examined, partly or wholly, as to whether there are train axles to be met with. If this is not the case, the line will be rendered clear'or, in other words, the signals will be:switched.in again. ,In connection herewith the arrangement is of such nature that after the return of the voltage, but prior to the energizing of the circuit controlling the signals, a train passing through the block section automaticallycauses the signals to beiswitched in againthrough'the medium of the special switch'system.

. According to a preferred examplelof perform ance of the present invention the specialswitch system comprises a time-relay which isactuated by the returning circuit voltage and which, after acertain time, causes the signals .to beswitched in. The period of operation of the time relay, after which the signals are switchedin again,

suitably exceeds the longest period of passage-of a train through the entire or through half the block section. This will "ensure that a train which is in the blocksection or atthebeginning or end of the latter at the moment atwhich the-circuit voltage returns, will have left the signals I are switched in again.

According to a further example of. performance of the present invention, the special switch system comprisesa relay or a relay set which is dependent, on the one hand, on the circuit volt-1 in any case. This, it is true, represents in the first; instance, a safeguarding of thetraffic but, on the other hand, it causes the grade crossing to be blocked for an unnecessarily long period. The result might be, particularly in. signaling installations for grade crossings, that, the road users may get used to the fact that, in spite of blocking. signal, no train is passin they will, in consequence thereof. lose the respect for these warning signals, so that the purpose of the safeguarding device loses in importance.

According to the present invention an arrangement is provided whereby when the current is again supplied to the system after an interruption, the signal circuit will not be immediage and, on the other hand, onthe switching state of the signaling apparatus or installation, in such a manner that it is actuated on the re turn of the circuit voltage and-thereby causes the signals to ,be switched infagain,- proyided, that the ignaling apparatus or installation is in a switching state which corresponds to the.- blocking section, or its beginning or end, beingclear. Thereby it will, furthermore, be attained that the change from the dark position of the signals will only be effected when thereis no train within .the installation,' i

Moreover, also in connection with the firsrt example of performance, the time relaycan ,be made to be dependent, apart from th'e circuit voltage, also'on the switching state of the sig-.

naling apparatus or installation, particularlyjin such a manner that the time relay, already'in operation when a train is entering the block secactuation of relay and therefore restoration of the system to normal position while there is a train in the block. Relay 5 in its off position prevents operation of several circuits at an improper time. Relays 3 and 4 cooperate to prevent a short circuiting of relay I when the circuit is not in normal condition, thereby preventing an improper operation. r

In connection with a proper operation the arrangement functions as follows:

The interruption of the contact, say KI by the approaching train, causes the relay! to be deenergized by opening the circuit IOI, I02, I03. In connection herewith contact I2 of this relay produces a short circuit through conductors I06, I05, switch 42, conductor I04, switch 52, switch 24 and conductor I04 for its relay which thus, in the first instance, remains in the release position, Whilst contact I I switches the free signal W off and the warning signal R on. The circuit of the free signal W includes conductor II3, switch 2|, conductors II4, II4a, II5, switch 55, and conductors H6 and H1; The circuit of the warning signal R includes conductors II2a, II8, 0a, switch 4|, and conductor H9. Thiscondition will remain, until the first tra -in axle causes the relay 2 to respond by coining in contact with the insulated bar or rail A. This causes the relay 3 to be switched in by contact 22 and the short circuit of the relay I opened by means of contact 24, so that the relay I can now respond again, in connection with which the contact 2i is instrumental'in causing the warning si nal R to remain switched 'on. The contact 22 closes the circuit through conductors 303, 302, 30I and 301 to the positive terminal. The relay 3 is already connected to the negative terminal through conductor 304, switch 54 and conductors 305 and I". Contact 2I engaging contact 2") closes the circuit of the warning signal R through conductors 8b, H4 and HM, switch II, conductor II5, switch 55 and conductors H6 and II! thereby supplying current to the warning signal R. When the last train axle leaves the insulated rail A, the relay 2 is released or dropped, so that the contact 2| switches over from the warning signal R to the free signal W by moving from contact 2Ib to contact 2| a. The relay 3 remains pulled up via its own contact 32 and contact 43 in spite of the interruption of contact 22. The holding circuit involved includes conductor 3I0, switch 32, conductor 306, switch 43 and conductor 30I which connect one side of the relay 3 to the positive terminal. When the vacating train passes over the railcontact K2, the relay'I drops again and switches in the time relay 4 (see Fig. 2a) by means of contact I 3, the time relay producing for itself, for a period determined by its adjustment, a holding circuit via its contact 43, conductors 30I and 406 and causing the safe signal W to remain switched in by means of contact M by closing the circuit through contact 4Ib, conductors Il4b, H4, switch 2| and conductor II3 on the one hand and through conductor H0, switch II, conductor H5, switch 55 and conductors II 6 and II! on the other hand. The changing over of contact 43 to contact 43a prepares the release of relay 3 which is still. pulled up via the contact I4. Release is prepared because contact 32 is now connected to the positive terminal only through conductor 309, switch I4 and conductor 308. The connection through conductors 306, 302 and 30I, is broken by the movement of contact 43 from contact 43b. After the train has passed over the contact K2, the relay I will respond again in the first instance. After a certain time, also the time relay 4 will be caused to stop again as contact 43 opens the-holdinggcircuit through conductors 30I and 406; so that the normal position of the installation will be re-' stored again. If the relay 4 should completeone rotation and contact 43 open its holding circuit before the train has passed over the contacts K2, it can, because the relay 3 is still pulled up via the contact I4, respond again, in order to drop once more after a certain time and to restore the original condition of circuits controlled by it."

The relay 2, connectedto the insulated rail A, can also be connected in series'withthe relay I in the current'loop and can be so designed that, when the contacts KI, K2 are interrupted, re-' mains pulled up via resistances shunted across the contacts and only drops, when the insulating rail is passed over or the cable is fractured in the current loop, so that in this way a permanent control of the closed circuit current loop is ensured.

If the voltage of the current source S fails whilst the installation is in any position, the closed circuit current relay 5will release all con-' tact elements controlled by it. It should be noted, that" thereby the circuit of the relay 5,via which' the latter is fed during normal operation, is interrupted by its own contact 5| of the relay 5'. By means of three further contacts 52, 54, other cir-' cuits are opened. Contact 52 opens the short circuit of relay I which short circuit includes contacts I2, 42, 53, 24 and conductors I06, I05, I04b, I04a and I04. Contact 54 opens the circuit of relay 3 by disconnecting conductors 304 and 305. Contact 55 opens the circuit H5, N6 of signal lamps W and R. At the same time contact 53 prepares the holding circuit including the conductors and switches 203, 53, 204, I5, 205 for relay 2. This circuit is open at I6 but ready for closing when relay I is energized. As soon now as the voltage returns to the feed circuit, the relay I is fed with current and responds. This will cause atthe contact I6 the prepared circuit to be closed for the relay 2 "which thus also pulls up; lnaddition thereto the time relay 6 will respond via contact 56 and conductors60 and 60I and th'ere by be started, in connection with whichit soon closes at the contact 6 I 'a holding circuit through conductors 60Ia and 603. After a prolonged period contact 62 is closed and the relay 5 switched in thereby through'conductors 504, 501. The responding relay 5 producestogether with the contact 5| a holding circuit and also leads back into their normal conditions all'other circuits controlled by it, particularly closing the circ'uit'for the signal lamps W, R, through contacts 55, II, 2I and 4| and conductors'I'I5, H4, H3, H0 and H8.

If, prior to the complete run-down of the time motorrelay 6, a train passes into the block section, e. g. via contact KI, the relay"! will, as usual, drop. This will at the contact I5 cause the operating circuit ofthe relay 5 to be closed already inadvance and'the release of the installation prepared already at that moment. "Thecircuit includes conductor 508, contact I5, conductor 501, contact 25, conductor'506', contact 44 andconductors 505 and 50L Note that contact 25 is still held closed by relay 2. As relay 5 is thus energized the holding circuit of relay 2 is opened at contact 53 and the complete system is in normal operation. The fact-that motor relay 6 is still running is immaterial.

Fig. 1a represents another modus of connection of the time relay 6, in which the latter is also rendered dependent on a relay of the signal connection, i. e. the motor timerelay 4, by means of the contact 45. This will cause the time relay 5 to be temporarily arrested when the relay 4 responds. r

In the arrangements described so far one relay 5 and one relay 6 each were provided for the restoration of the signal circuits and for the retardation of the restoration. According to a further development of the present invention an essential simplification can be attained by designing the release relay itself as a time switching relay. For this purpose rotary time switching devices, cam discs and the like, can beused. In this case, however, an arrangement of resistances and condensers provesof special interest, in connection with which the advantage is at tained, that intermediate connections of whatever description of the time switching device will be impossible. In connection with the revolving contact-paths it can, as a matter of fact, happen, that the time switching device, at a circuit interruption, will find itself in an intermediate position and permanently remains in the latter. In a condenser, however, the charge of the latter will escape after a short time via the-connected resistances or also via its own leaking resistance automatically, so that the arrangement always permits of utilizing the full charging time. Apart therefrom, however, condensers are considerably cheaper than revolving time switching devices, so that the price for a release arrangement of the signaling plant can be reduced to a fraction.

A circuit arrangement of this nature is illustrated in Fig. 3. The connection of the track relays is identical with that of the examples previously referred to. If the source of power fails, the relay 5, which is designed as closed circuit current relay, also drops and opens its contact 5|, so that it cannot immediately pull up again at circuit return. In connection therewith the relay 5 produces an interruptiton with the aid of the contact 52in the shorting circuit of the relay I and prevents, by means of the contact 54 the auxiliary relay 3 from responding, and by contact 55 opens the signal circuit. The contact 52 is characterized by the effect, (because it is Open) that, at the the line the relay I can pull up at once and simultaneously cause its contact l5 to change from its position b into the positon l5a. This will cause current to flow via the resistance W1 through the relay 5 by conductors 5| I and 5l2, in connection with which, however, a corresponding retardation of the pull-up of the relay 5 will be caused by means of the condenser C and the resistance W2, which are located in circuit with the contact 55 by conductor 504, closed at that time, and in parallel with the relay 5. The contact It will now, through conductors 204, 283 and contact'53, furthermore, cause the relay 2 to be energized which, however, will occur before the relay 5 acts. When, afterits retardation, relay 5 has definitely pulled up, the contact 53 will open the circuit of the relay 2'and cause the latter to drop again. If now, at the moment of the circuit return while relay 2 is energized a train passes over one of the switching-in contacts K1 or K2, the dropping of the relay I will cause current to be immediately fed to the relay 5 via conductor 509, contact 25, conductor 506, contact 44, conductor 5"), contacts l5b, l5 and conductor 5 whereby the return of power in retarding efiect of the condenser C will be avoided. The relay 5 will then pull up without any retardation. For the purpose of ensuring as extensive a retardation as possible, the relay 5 should suitably be of such dimensions, that it pulls up closely below the operating voltage, in connection with which the resistance W1 is correspondingly small, e. g. 5-10% of the relay resistance. The resistance W2 must be so chosen, that it is neither too great nor too small. The optimum value is best determined by test. Naturally, C should be as great as possible, but it has been ascertained, that retardations of from 1 to 2 minutes, as they are being considered for the purposes under consideration, are attainable even in conjunction with moderate condenser values.

What I claim, is:

1. In combination a stretch of railway track including a section intersected by a highway, a traflic signal adjacent the highway, an electrical circuit including switch means controlling said signal, train operated tripping elements positioned to be operated by a train passing through said section arranged to control the switch means of said electrical circuit, a-current source from which said electrical circuitreceives power, a relay normally energized from the current source to maintain the switch means of said electrical circuit in operative condition, a safety control circuit including switch control means normally energized from the current source to maintain said circuit in operative condition, the switch control means of the safety control circuitincluding a switch and means to open said switch upon failure of the voltage in the currentsource, and means for restoring current to said safety control circuit upon restoration of the voltage in the current source including a time delay ,relay, together with an auxiliary circuit including control means operated by the trainoperated tripping element first engaged by a train entering the section to immediately re-energize said control circuit upon entrance of a train into the section.

2. In combination a stretch of railway track including a section intersected by a highway, traffic signals including warning and free signals, signal circuits including switch means arranged to control said trafiicsignals, a current source from which saidcircuits are energized, a control relay normally receiving energy from said current source, switches operated by said relay arranged when the relay is energized to control said signal circuits to maintain the same in operative con dition and arranged when said relay is de-energized to maintain said signal circiuts in inoperative condition, switch means to open the circuit from the current source to' said control relay automatically operative upon failure of voltage in the current source, switch meansfor re-connecting said control relay to the current source upon restoration of voltage in the current source including a time delay relay, and auxiliary means actuated in response to the movement of a train into the section cooperating with said Iast mentioned means for re-connecting the control relay independently of the time delay relay 3. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals-located at the intersection, a current source for supplying current to said signals, means for controlling the supply of current from said current source to said signals including a safety control relay, said control relay being arranged to be Lie-energized upon failure of voltage in the current source, and means for causing said control relay to be ire-energized upon restoration of voltage in the current source including a time delay relay.

4. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, a current source for supplying current to said signals, means for controlling the supply of current from said current source to said signals including a safety control relay, said control relay being arranged to be de-energized upon failure of voltage in the current source, means for causing said control relay to be re-energized upon restoration of voltage in the current source including a time delay relay, and means to re-energize said control relay independently of the time delay relay including a train operated switch whereby the switches may be restored to position during operation of the time delay relay.

5. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, signal control circuits for said warning and free signals including a train operated switch positioned to be operated by an approaching train connected to cause energizing of said warning signal and deenergizing of said free signal, a safety control switch connecting the current supply and the signal control circuits, means for opening said switch upon failure of current in the current supply, and means actuated by said train operated switch to cause closing of said safety control switch.

6. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, electrical circuits for controlling said warning and free signals including a safety control relay and switches controlled thereby for supplying current from the current source to the control circuits, said relay having a holding circuit, and means for re-energizing said relay upon restoration of voltage in the current supply after failure thereof including a time delay relay and electrical connections to said current source controlled thereby.

7, In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, means normally controlling the Warning and free signals including a train operated means arranged to be operated by an approaching train to energize the warning and de-energize the free signal and a train operated means arranged to be operated by a train passing the crossing to energize the free signal and de-energize the warning signal, a source of current from which said signals are energized, safety control means associated with said source of current and said signals to prevent operation of said signals under predetermined conditions, means for restoring said safety control means to normal condition to permit operation of the signals as controlled by the train operated means comprising a time delay relay arranged to be set in operation by restoration of the voltage in the current source after an interruption, and means arranged to be set in operation by operation of the first mentioned train operated means and operative to restore the safety control means to normal condition independently of the time delay relay.

8. In combination a stretch of railway track including a section intersected by a highway, a highway crossing signal located at the intersection, train operated circuit controllers, relays operatively connected to the circuit controllers to be controlled thereby, means controlled by said relays for operating the signal, means for supplying current to the relays from a current supply, means for supplying current to the crossing signal including a switch, means for closing said switch after an interruption of the supply circuit has taken place and the current supply voltage has been restored including a time delay relay, and means operated by the train operated circuit controllers for closing the circuit between the current supply and the crossing signal independently of the time delay relay.

9. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, a current source for supplying current to said signals, means for controlling the supply of current from said current source to said signals including a safety control relay, said control relay being arranged to be deenergized upon failure of voltage in the current source, means for causing said control relay to be re-energized upon restoration of voltage in the current source including a time delay relay, means controlled by a train approaching the intersection for connecting the warning signal to the current source and disconnecting the free signal, and means controlled by a train beyond the intersection for connecting the free signal to the current source and disconnecting the warning signal including a time delay relay which temporarily closes an electrical connection between the current source and the free signal.

10. In combination, a stretch of railway track including a section intersected by a highway, highway crossing signals including warning and free signals located at the intersection, a current source for supplying current to said signals, means for controlling the supply of current from said current source to said signals including a safety control relay, said control relay being arranged to be de-energized upon failure of voltage in the current source, means for causing said control relay to be re-energized upon restoration of voltage in the current source including a time delay relay, means controlled by a train approaching the intersection for connecting the warning signal to the current source and disconmeeting the free signal, and means controlled by a train beyond the intersection for connecting the free signal to the current source and disconheating the warning signal including a train operated switch, a time delay relay, a circuit controlled by the time delay relay for temporarily connecting the free signal to the source of power, and a train operated device for energizing said time delay relay.

ERNST WILCKENS. 

